Process of annealing steel



Patented Sept. 29, 1925.

PATENT OFFICE.

WATSON M. SHOPPART, 0F GENEVA, OHIO.

PROCESS OF ANNEALIN G STEEL.

No Drawing.

T 0 all whom it may concern:

Be it known that WA'rsoN M. SHorrAn'r,

with air slacked lime, the piece of steel to be treated being placed in the center of the lime and completely covered thereby. The case is then closed and rendered air tight by cementing the same with fire clay or the like. This closed air tight case is now placed in a coke or hard coal fire (no blast) and is heated to about 1400 F., and the heat treatment is continued for about twelve hours.

The closed air tight case is next Withdrawn from the fire and remaining air tight, the steel is allowed to gradually cool to normal temperature, care being taken to keep the case out of any draft, before opening and unpacking the steel. lVhen the steel is removed from the case, after this treatment, it will be found to be perfectly annealed, and ready for machining.

The tool which may be produced from the steel thus annealed, is next machined perfectly, not allowing for any shrinking or expanding.

It the tool thus machined from the annealed steel is to be used in hot work, place the same in aclear coke fire, and let it become a cherry red. Then lay the heated tool down in a dry place, and allow it to cool gradually without contact with drafts of Application filed December 11, 1924. Serial No. 755,344.

air, until it returns to normal temperature.

If the tool thus machined from the annealed steel is to be used in a cold work, it should be heated to slightly below a cherry red, and then allowed to cool slowly in the air, in a dry place, without contact with drafts, until it returns to atmospheric temperature.

It is to be understood that the form of the intention herewith shown and described, is to be taken as a preferred example of the same, and that various changes may be resorted to in the order of the steps of themethod, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, what is claimed is:

1. The herein described method of temper ing hard steel, which comprises enclosing a mass ol such steel in a bed of air slacked lime with the exclusion of the air, heating the steel thus enclosed to a temperature of approximately 1400 F. for approximately twelve hours, allowing the steel thus treated to cool in the air slacked lime mass with the exclusion of the air, and then removing the cooled mass from the presence of the lime.

2. The herein described method of tempering hard steel, which comprises enclosing a mass of such steel in an air tight case filled with air slacked lime, heating the steel thus 7 enclosed to a temperature of approximately 1400 F. for approximately twelve hours, allowing the steel thus treatedto cool in the air tight case, removing the cooled mass from the presence of lime, reheating the steel to approximately cherry red temperature, and allowing the reheated steel to gradually cool to atmospheric temperature.

In testimony whereof I affix my signature.

\VATSON M. SHOPPART. 

